What is the Difference Between Secondary Oocyte and Ovum?

The main difference between a secondary oocyte and an ovum lies in their maturity and the stages of meiosis they represent. Here are the key differences:

• Secondary Oocyte: A secondary oocyte is an immature female gamete produced from a primary oocyte during oogenesis. It is formed after the first meiotic cell division, which results in a haploid number of chromosomes (23 chromosomes). The second phase of meiosis is paused until the secondary oocyte is fertilized with a sperm.
• Ovum: An ovum, on the other hand, is a mature female gamete produced after the second meiotic cell division. Soon after fertilization, the secondary oocyte undergoes meiosis II and produces the mature egg cell called the ovum. The ovum nucleus fuses with the sperm nucleus to produce the zygote, which can develop into an individual.

In summary, a secondary oocyte is an immature egg cell that undergoes the first division of the meiotic cycle, while an ovum is a mature egg cell formed after the second division of the meiotic cycle. Both secondary oocytes and ovum contain 23 chromosomes and are haploid cells produced inside the female reproductive organ as a result of female gametogenesis.

Comparative Table: Secondary Oocyte vs Ovum

Here is a table comparing the differences between a secondary oocyte and an ovum:

Both the secondary oocyte and ovum are products of female gametogenesis and are haploid, containing 23 chromosomes each. The secondary oocyte is an intermediate product of oogenesis, while the ovum is the final, mature product. The secondary oocyte undergoes meiosis II and produces the ovum after being fertilized by a sperm.